Apparatus and method for hydrolysis of a protein containing raw material and application of the resulting hydrolysis products

ABSTRACT

Apparatus and methods for hydrolyzing protein-containing raw material into water soluble protein and other products. The apparatuses and methods comprise an optional collection or processing stage in which protein-containing raw material, such as fish or animal carcasses from food production plants, are collected and optionally processed. The raw material is then reacted with one or more enzymes to hydrolyze the protein present, after which the one or more enzymes are inactivated and the components separated. The processes and apparatuses, which can be run as a batch processes or, advantageously as a continuous processes, can yield water soluble protein, oils, bone meal and other products that have utility as food or food additives.

BACKGROUND

This disclosure relates to plants and methods for hydrolysis of proteincontaining raw material, and to uses of the hydrolysis products obtainedtherefrom.

Various batch hydrolysis processes are known, each having certaindisadvantages, such as prolonged processing time, low yields of solubleprotein, deficient product quality or flavor, high fat content, andinefficient use of resources. This disclosure provides apparatuses,methods, and systems that provide hydrolysis of protein-containingmaterial, such as fish, animal and plant materials, and hydrolysisproducts resulting therefrom.

SUMMARY

Provided herein are embodiments of apparatuses and methods thathydrolyze and separate a reaction mixture comprising (i) aprotein-containing fish, animal or vegetable raw material and (ii)proteolytic enzyme. The raw material may be in the form of by-productsor waste products from the processing of foodstuffs. The apparatuses andmethods comprise an optional collection section or area, where the rawmaterial (typically in pieces, such as fish or animal carcasses) iscollected and optionally processed to reduce the size of the pieces ofthe raw material collected, a hydrolysis section or area that hydrolyzesthe reaction mixture, an inactivation section or area that substantiallyinactivates the enzyme present in the reaction mixture, and a separationsection or area where at least a portion of the reaction mixture isseparated into at least one liquid component that comprises watersoluble protein. In other embodiments, the water contained in the liquidportion comprising the water-soluble protein is evaporated to yieldconcentrated solutions comprising hydrolysate or dried to produce solidhydrolysate.

In other embodiments, the collection area and/or the hydrolysis areaand/or the inactivation area and/or the separation area is capable ofmaintaining and does maintain the reaction mixture such that anyemulsion present in the liquid component of the reaction mixture isbelow a predetermined level. In one embodiment, any emulsion present isat or below 5% of the reaction mixture, more preferably at or below 2%,even more preferably at or below 1% and most preferably at or below0.5%. In another embodiment, any emulsion present in the reactionmixture is at or below 3%.

In some embodiments, the particle size of the raw material may beselected to reduce, minimize, or avoid emulsions from forming. Forinstance, in an embodiment of the invention where the raw material usedcomprises fish, the raw material may be loosely ground, chopped, or cutso that the size of the raw material pieces or particles is about 16 mmor greater in width. In one embodiment, the size of the raw material isfrom about 16 to about 50 mm in width, and in another embodiment theaggregate size of the raw material is about 30 mm or greater in width.Measurement of the size of a piece of raw material may be in anyselected direction or dimension. Thus, a long strip or sheet of rawmaterial that is 30 mm wide in only one direction may be acceptable foruse with the present invention.

Skilled artisans would appreciate that the aggregate size of the rawmaterial particle size may be achieved, controlled, or determined inseveral ways. For instance, processes used to grind raw material mayhave openings through which the raw material is forced to pass. The sizeand or shape of the openings thus can be varied accordingly to arrive ata desired aggregate size of raw material pieces. Similarly, choppingprocesses likewise may control how the raw material is cut or chopped.The size of the raw material pieces or particles may also be measured,such as by using a caliper or any other suitable measurement tool.Alternatively, the size of the raw material may be determined bycorrelating the weight of a piece of raw material to a size.

In some embodiments of the invention the use of larger sized rawmaterial does not appreciably increase the time needed to hydrolyze thereaction mixture. For example, in one embodiment of the invention a 50%increase in the size of the raw material pieces may result in less than10% of an increase in time needed to hydrolyze it in a reaction mixture,and more preferably results in less than a 5% increase in time.

In other embodiments, the apparatus is capable of hydrolyzing two tons,three tons, four tons, or five tons or more of raw material per hour.Apparatuses of the invention also may be capable of hydrolyzing evengreater amount of raw material per hour, such as eight tons, 10 tons, 13tons, or 15 tons or more of raw material per hour.

In addition to being capable of hydrolyzing a high capacity of rawmaterial per hour, other embodiments of the invention are capable ofoperating at a desired capacity for extended periods of time. Forexample, in one embodiment an apparatus is capable of converting ortransforming raw material into useful products continuously for at leastabout 72 hours. In another embodiment, an apparatus is capable ofoperating continuously for about 7 days or more. In yet anotherembodiment the apparatus is capable of operating continuously for about2 weeks or more.

In another embodiment, the hydrolysis area or section comprises at leastone hydrolysis reactor. The hydrolysis reactor may be substantiallytube-shaped, although other shapes or configurations also may be used.In other embodiments, the hydrolysis area or section comprises a feederscrew for conveying a reaction mixture of enzyme and raw materialthrough the hydrolysis area or section of the apparatus.

Feeder screws also may be used in other sections or areas of theapparatus, such as in the inactivation area or section described morefully below. For example, in one embodiment one or more feeder screwsmay be used for conveying the reaction mixture through the inactivationarea. The feeder screw may remove reaction mixture comprising solidcomponents, such as bones, and a liquid component for separation.

In another embodiment, the reaction mixture can include a fatty layerthat can be separated, e.g., by pumping and/or decanting.

Yet other embodiments provide apparatuses and methods which provideyields of water-soluble protein of at least about 50%, 60% and 70% ormore by weight based on the weight of protein in the raw material.

Yet other embodiments provide that the pH of the reaction mixture is notadjusted from its existing state. Yet another embodiment provides thatthe pH of the raw material is not adjusted or that the pH of the rawmaterial and the pH of reaction mixture is not adjusted from itsexisting state. For example, the pH of the raw material and reactionmixture in such embodiments is between about 6 and about 9, preferablybetween about 6.5 and about 8 and more preferably between about 7 and 8or about 7.

Yet other embodiments provide protein-containing products that compriseor contain amino acids derived from animal proteins, such as from fish.Other embodiments of the invention comprise providing protein-containingraw material from plants. Also disclosed are embodiments in which suchproducts are used as food or as a nutritional supplement for humans oranimals.

Other features and advantages of the embodiments of this disclosure willbecome apparent from consideration of the following description taken inconjunction with the accompanying drawings and claims.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram according to one embodiment of an apparatusand process for hydrolyzing proteinaceous raw material, such as fromanimals, plants, or the like.

FIG. 2 is a block diagram according to another embodiment of anapparatus for removing metal parts from raw material.

FIG. 3 is a block diagram of another embodiment that includes a reactorthat keeps the liquid phase in circulation.

FIG. 4 is a side elevation view of a hydrolysis reactor and aninactivation reactor according to one embodiment.

FIG. 5 is a block diagram of another embodiment that includes removal ofoil from the hydrolysis assembly.

FIG. 6 is a diagram showing an inactivation reactor, a slanted filterscreen and separate solid and liquid collection containers for use in anapparatus and process for hydrolyzing animal or vegetable raw material.

FIG. 7 illustrates alternative configurations and devices to aid inmoving, conveying, or transporting raw material or a reaction mixture.

FIG. 8 is a partial view of a portion of a screw or auger having ascoop, spatula, ledge, or sheet arranged along the periphery of thethread.

FIG. 9 is a diagram showing a variation of the filtration system of FIG.6.

DETAILED DESCRIPTION

In this section, detailed discussion of various embodiments is provided.From the following discussion, skilled artisans readily will recognizenumerous modifications, permutations and alterations that may be made tothe various specific embodiments described.

A. Raw Material

The apparatuses, systems and methods described herein are useful forhydrolyzing proteinaceous (i.e., protein-containing) raw material intouseful products, such as water-soluble proteins, peptides and aminoacids. As used herein, the term “raw material” means any proteinaceousraw material from any one of or from several of the five kingdomsincluding plant, animal, protists, fungi, and bacteria, prior to theaddition of enzymes that hydrolyze, convert, or transform the rawmaterial into useful products. Thus, raw material may include, but isnot limited to, non-enzyme-treated material derived from plants oranimals, including fish, that are a source of protein, oil rich inunsaturated fatty acids, and bones.

Raw material derived from fish products and other marine organisms, suchas crustaceans, poultry products, beef products and products of otherruminant animals, lamb products, swine products, and microbial products,such as blue-green algae, are well-suited for the purposes describedherein. In the context of fish raw material, the raw material caninclude, for example, bones, heads, tails, and viscera, as well as anyother waste product produced from the processing of fish for humanconsumption. The raw material can also be, for example, slaughterhousewaste with meaty bones, or vegetable raw material.

In general, enzymes and water may be added to the raw material to form areaction mixture that can hydrolyze the raw material under properconditions. In one embodiment, apparatuses, systems and methodsdescribed herein are useful for processing raw material derived from orcomprising fish to provide useful products that are oil rich inunsaturated fatty acids, such as omega-3 fatty acids, which have beenshown to reduce the incidence of cardiovascular disease. In particular,raw material derived from fatty fish, including but not limited tomackerel, lake trout, herring, sardines, albacore tuna, and salmon, arehigh in two kinds of omega-3 fatty acids, eicosapentaenoic acid (EPA)and docosahexaenoic acid (DHA). When fatty fish are included in the rawmaterial, the apparatuses, systems and methods described herein arecapable of producing an oil component or phase that may be separated(e.g., by pumping out of the apparatus and/or decanting) and used toproduce food additives containing omega-3 fatty acids, or furtherprocessed, e.g., to extract oil soluble vitamins.

In addition, fish is a source of the essential amino acids valine,leucine, isoleucine, lysine, methionine, threonine, tryptophan, andphenylalanine. In addition to the essential amino acids, hydrolysatesdescribed herein may also include significant levels of other aminoacid-like compounds, such as taurine, which is used to absorb fats andfat-soluble vitamins. Taurine has been found to have many benefits,including reversing abnormal blood vessel response associated withcigarette smoking. Thus, the hydrolysates described herein can be usedto produce taurine tablets or other taurine-containing products.Preferably, the taurine tablets or other taurine-containing products aresuitable for human consumption. As used herein, the term “hydrolysates”refers to water-soluble proteins, peptides and amino acids.

In addition, taurine is an essential nutrient for cats because, unlikedogs and humans, for example, cats cannot synthesize their requiredamount of taurine to meet their needs. In contrast, taurine can beproduced from the essential amino acids methionine and cysteine inhumans and dogs. Cats, however, lack the enzyme for this reaction, sotaurine must be obtained from food. Accordingly, the hydrolysatesdescribed herein can also be used to make food additives for cats.

B. The Collection Area

The apparatuses, systems or methods of this disclosure can include oneor more collection or preparation areas. The collection or preparationarea simply connotes a place, e.g., an assembly, section, stage orseparate housing, chamber, reactor or unit, where raw material can becollected, and optionally further processed, prior to being subjected tohydrolysis. The collection area can be in direct or indirectcommunication with the hydrolysis area, and located either nearby orremote from the hydrolysis area. Thus, the collection area can bedirectly connected to the hydrolysis area, or connected through one ormore intermediate sections, connections or conduits. Alternatively, thecollection area can be remotely located from the hydrolysis section,e.g., at a fish processing plant or animal slaughterhouse, and the rawmaterial, with or without processing on-site, may be simply transportedand supplied to the hydrolysis area, with or without further processingthere.

The collection area thus can include pre-hydrolysis processing steps,such as mincing, grinding, chopping, cutting, blending or othermechanical actions that result in size reduction of the raw materialpieces, thereby resulting in a greater effective surface area of the rawmaterial to allow more effective contact between the raw material piecesand the one or more enzymes. In addition, the raw material pieces havedimensions that avoid or minimize emulsification when conveyed throughthe hydrolysis area, as described below. Raw material having a high fatcontent, such as a fat content of about 10% w.w. (wet weight) or more,and more preferably 15% or more, may be processed into larger sizedpieces in order to help reduce, minimize, or avoid emulsification. Forexample, raw material pieces may have dimensions from about 15 mm toabout 50 mm, preferably from about 20 mm to about 40 mm and from about25 mm to about 35 mm in at least one direction or dimension. In otherembodiments, even larger raw material pieces may be utilized and itsurprisingly has been found that pieces of up to 300 mm in length ormore, such as whole fish backbones, can be processed withoutsignificantly extending or increasing the time it takes to hydrolyze theraw material. In certain cases, whole fish and other similarly-sized rawmaterial pieces may be utilized.

Alternatively, smaller sized raw material may be used in someembodiments, such as when the raw material has a low fat content thatpresents a lower likelihood of emulsification than higher fat contentmaterial. Thus, in some embodiments the size of the raw material piecesmay be smaller than 15 mm. For purposes of this aspect of the invention,a low fat content raw material has a fat content of about 5% w.w. orless, and more preferably is about 2% w.w. or less.

The process of collection, including optional pre-hydrolysis processing,can be adjusted or varied to control the amount of emulsification of anyliquid present in the raw material as a result of pre-hydrolysisprocessing. Emulsification can be controlled, for example, by minimizingvigorous or turbulent mixing or processing or by utilizing larger piecesof raw material to reduce emulsification from fine grinding or mincing.In addition, chemical demulsification agents or additives may be used todecrease, prevent, or eliminate emulsification. Chemical demulsificationmay include the addition of one or more chemical demulsifying agents oradditives to the raw material or reaction mixture in order to enhancephase separation. If chemical emulsion control agents or demulsifiersare used, they should be chosen to minimize emulsion or other effects inthe desired final products.

Emulsion control also can include, alternatively or in addition,demulsification by known physical means. For example, physicaldemulsification may include gravity settling and/or electrostaticcoalescence. The principal idea behind the later method is to enhancephase separation through electrically-aided charging, migration,collision, and thus coalescence of dispersed phase droplets within thesystem.

In various embodiments, water may be added to the raw material in thecollection area. If the temperature of the raw material is low (e.g., ifit is frozen or refrigerated), the water may be heated in order to bringthe temperature of the raw material or reaction mixture to a desiredtemperature or temperature range that is more conducive or suitable forhydrolysis. For example, the temperature of the reaction mixture may bebetween about 20° C. to about 85° C. after the addition of water andenzyme to the raw material. Preferably, the reaction mixture temperatureis between about 30° C. and about 70° C., and more preferably is fromabout 50° C. to about 60° C. after the addition of water and enzyme tothe raw material.

Enzymes also may be added to the raw material in the collection area. Asdiscussed below, water and/or enzymes alternatively or additionally maybe added to the raw material after being introduced into the hydrolysisarea. The addition of enzymes and water to the raw material in thecollection area may allow the hydrolysis process to begin. Likewise, thetemperature or other conditions of the reaction mixture may becontrolled so as to control or limit the extent of hydrolysis that takesplace prior to introducing the reaction mixture to the hydrolysis area.Controlling the hydrolysis process may permit the addition of enzymesand/or water when it is convenient or desired while minimizing,reducing, or avoiding altogether the possibility of emulsificationduring handling, transport, or storage of the reaction mixture prior tointroducing it into a hydrolysis area.

C. The Hydrolysis Area

The apparatuses and methods of this disclosure can also include one ormore hydrolysis areas that receive raw material from the optionalcollection area. The hydrolysis area simply connotes the place, e.g., anassembly, section, stage, separate or connected housing, chamber,reactor or unit, where the raw material may be subjected to hydrolysis.Thus, the hydrolysis area is typically located after the collection area(if one is provided).

As discussed above, the hydrolysis area may be located either nearby orremotely from the collection area. In addition, a collection area andhydrolysis area may be integrally connected to each other so that rawmaterial or reaction mixture may be found in either area. Thus, acollection area and hydrolysis area may be in fluid communication witheach other or alternatively may be identified by substantially the sameequipment or components in an apparatus, system, or method of thepresent invention. For example, a container or supply system having rawmaterial may also be a hydrolysis area after the addition of enzymes andwater.

One or more enzymes may already be mixed with the raw material prior toentry into the hydrolysis area, may be added to the raw material in thehydrolysis area, or both. The addition of one or more enzymes, andoptionally water, to the raw material forms a reaction mixture, i.e.,reaction mixture is different from the raw material in that the reactionmixture additionally comprises one or more enzymes. Likewise, water,including water optionally heated to between about 20° C. to about 85°C., may be added to the raw material before and/or during residence inthe hydrolysis area. As discussed above, the temperature of the waterand/or raw material may be adjusted to other temperature ranges thatlikewise may be suitable for hydrolysis to occur. Whatever the sequenceof admixture, the raw material and enzyme are contacted and presenttogether as a reaction mixture in the hydrolysis area.

In another embodiment, one or more enzymes also may be added to the rawmaterial by siphoning or re-circulating a liquid portion of the reactionmixture having active enzyme from a first location of the hydrolysisarea to a second location. For example, the liquid portion of thereaction mixture may be recirculated from near the exit end of thehydrolysis area by reintroducing such liquid portion into or near theentry end of the hydrolysis area.

Alternatively, liquid from the hydrolysis area may be siphoned orre-circulated into a collection area in order to help initiatehydrolysis, to help thaw or warm the raw material, or both. Typically,enzymes that are contacted with the raw material and facilitatehydrolysis are not consumed in the hydrolysis, or at least may be reusedseveral times before the enzyme becomes unable to hydrolyze rawmaterial. Accordingly, such enzymes that are already utilized in thehydrolysis of raw material retain its activity and thus are a viablesource of active enzymes.

Re-circulating an enzyme can be at least a partial or completesubstitute for adding new enzyme, i.e., the re-circulated enzyme can beintroduced into the hydrolysis area or the collection area prior toconveyance to the hydrolysis area as a substitute for or in addition tonew enzyme. For instance, in one embodiment of the invention, about 30%or more of the enzyme in a hydrolysis area is re-circulated and reused.Even higher amounts of enzymes may be re-circulated or reused, such asabout 50% or more, or 80% or more of the enzyme in the hydrolysis area.

Under suitable conditions, one or more enzymes may react with the rawmaterial to yield a hydrolysate or hydrolysis product, as well as othersoluble or insoluble products. As used herein, the terms “hydrolysate”and “hydrolysis product” may be used interchangeably and refer tosoluble proteins, peptides and/or amino acids in water. As discussedabove, the reaction mixture is deemed to include the entire contents ofthe hydrolysis area including raw material, enzyme, other constituents,such as water, hydrolysis product so formed, and solids, such as bonesthat are left following hydrolysis. The hydrolysis area forms anenvironment that facilitates hydrolysis, and according to one embodimentsubstantially controls emulsification of the reaction mixture topredetermined levels while hydrolyzing the reaction mixture. Emulsioncontrol and/or demulsification can be effected substantially asdescribed above.

The hydrolysis area can include various configurations and devices tochemically and/or physically aid in hydrolyzing the reaction mixture.The hydrolysis area also can include various configurations and devicesto aid in moving, conveying, or transporting the reaction mixturethrough the hydrolysis area. In one embodiment consistent with acontinuous process, reaction mixture can be advanced through ahydrolysis area toward an inactivation area by a transport mechanismand/or provide gentle agitation and/or mixing, e.g., conveyor belts,vibration belts, microwave or ultrasound transmission systems, tumblers,and the like, while avoiding or minimizing the formation of an emulsion.

For example, the hydrolysis area may utilize an Archimedes screw, singleor twin screw pumps, or the like. Thus, an auger may turn within ahousing to move and/or gently mix the reaction mixture. Likewise, ahydrolysis area may have a housing or sleeve with an internal surfacedefining a passageway through which the reaction mixture travels. Ratherthan using an auger to move and/or gently mix the reaction mixture,however, the internal surface of the housing may have a threaded channelthat accomplishes similar movement and/or gentle mixing of the reactionmixture by rotating the housing. This alternative embodiment, which isillustrated in FIG. 7A, thereby accomplishes a similar result as a screwpump without an internal moving part.

In another embodiment, shown in FIG. 7B, a loop of a bath, housing, orchannel may be used for a hydrolysis area. In this embodiment, a bath orchannel of reaction mixture is provided with moving screens, panels,containers, or the like moving therein. Raw material or reaction mixturemay be introduced at a first location of the loop and is moved throughat least a portion of the loop by the screens, panels or containers.Optionally, water and/or enzymes also may be added at this or anotherlocation in the hydrolysis area. The hydrolyzed components and solidremains may be removed from the hydrolysis area at a second location.

As described above, the reaction mixture can be moved by means of one ormore feeder screws or the like that advance the reaction mixture whilemixing it in a controlled fashion to promote or optimize contact betweenenzyme and raw material, and also while avoiding or minimizing emulsionformation. For example, the feeder screws can rotate clockwise in apredetermined first period of time or until certain parameters are met,and counter-clockwise in a predetermined second period of time or untilother parameters are met, to mildly agitate the reaction mixture.

The rate and period of time for the clockwise and counter-clockwiserotation may each be independently varied. For example, a time periodfor clockwise rotation may be longer, equal to, or shorter than the timeperiod of time for counter-clockwise rotation. Typically, the timeperiod for clockwise movement may be from about 120 seconds to about 30seconds, and more preferably about 90 seconds, while the time period forclockwise movement may be from about 90 seconds to about 30 seconds andmore preferable about 60 seconds. Rates of clockwise andcounter-clockwise rotation may be, for example, from about 3 revolutionsper minute (“rpm”) to about 0.10 rpm, and more preferably from about 0.5rpm to 0.75 rpm or about 0.66 rpm. The screws can continuously orintermittently provide such clockwise and counter-clockwise rotations.In these embodiments, the holding times in the hydrolysis section of theinactivation reactor may, therefore, be controlled by first allowing thefeeder screws to alternately rotate in one direction and the other, inorder thereby to transport reaction mixture in a step-by-step movementwhere the reaction mixture is carried slightly longer forwards than itis pulled back.

The material is contacted with one or more enzymes, i.e., the reactionmixture is allowed to react, in the hydrolysis area for a total periodof time from about 120 minutes to about 15 minutes, preferably fromabout 90 minutes to about 30 minutes, and most preferably from about 45minutes to about 50 minutes. Thus, the rotation rates, rotation timeperiods and conveyance lengths of the raw material through thehydrolysis area may be routinely determined by the skilled artisan toobtain the desired residence time of the reaction mixture in thehydrolysis area.

D. The Inactivation Area

The apparatuses or methods of this disclosure can include one or moreinactivation areas. The inactivation area simply connotes the place,e.g., an assembly, section, stage or separate housing, chamber, reactoror unit, where the enzyme in the reaction mixture is inactivatedfollowing hydrolysis. Inactivation can be carried out using variousmethods, such as increasing the temperature of the reaction mixture todenature the enzyme, thus substantially inactivating it, or by modifyingthe pH of the reaction mixture. As used herein, the phrase“substantially inactivating” means, for example, rendering the one ormore enzymes that have already been contacted with raw material to begreater than about 90% inactive, preferably greater than about 95%inactive, and more preferably from about 99% inactive.

When heating is used to inactivate, care should be taken that theresulting end products do not lose their nutritional value, i.e.,decompose or destroy the proteins, peptides and amino acids in thereaction mixture. Thus, the inactivation area should be adjusted tomaintain a temperature sufficient to inactivate the hydrolysis enzyme,for example, of above about 85° C. to about 100° C., preferably about90° C. to about 95° C. The heating temperatures to inactivate the one ormore enzymes can be maintained from about 0.5 minutes to about 45minutes, more preferably from about 1 minute to about 30 minutes, evenmore preferably from about 5 minutes to about 25 minutes, and mostpreferably from about 10 minutes to about 20 minutes. For example, an85° C. to about 90° C. temperature may be maintained for about 15minutes to inactivate the enzymes. Inactivating the enzymes by adjustingthe temperature of the solution is efficient because it also results ina raised temperature range which is desirable, for example, for thedecanter or tricanter separation (or other separation) as describedherein.

In another embodiment, one or more acids or bases are added to thereaction mixture to adjust the pH to substantially inactivate the one ormore enzymes. Typically, the enzymes used in this process areinactivated when the reaction mixture has a pH of less than about 4 andgreater than about 9.

In another embodiment, the pH range is not adjusted. This isadvantageous because it eliminates the need for acidic or basic solventswhich present, for example, environmental concerns regarding their useand disposal. Also such solvents can be costly. In this embodiment,where the pH is not adjusted, enzymes having optimal activity in thefollowing pH ranges may be used: having an optimal range pH of betweenabout 6 and about 9, preferably between about 6.5 and about 8 and morepreferably between about 7 and 8 or about 7.

The inactivation area can comprise a reactor or chamber having a singleinlet and single outlet for the reaction mixture, or it can be anapparatus that includes one or more separate inlets and one or moreseparate outlets that is capable of facilitating a continuous hydrolysisprocess. The inactivation area may be designed to permit either batch orcontinuous inactivation reaction, or both.

According to one embodiment, discussed in further detail below, an exitend of an inactivation reactor, i.e., where the inactivated reactionmixture exits the inactivation area, has at least one outlet for a solidmatter constituent, phase or component (such terms being used todescribe the part of the reaction mixture that comprises solids) of theinactivated reaction mixture and at least one outlet for a liquidconstituent, phase or component (such terms being used to describe thepart of the reaction mixture that comprises liquid) of the inactivatedreaction mixture, positioned at a distance from the outlet for the solidmatter component. The outlet for the solid component is positioned at adistance from the outlet for the liquid component to sufficiently avoidor minimize mixing of the solid components with the liquid-onlycomponents. Accordingly, in one embodiment, a continuous enzymatichydrolysis of a raw material, such as meaty broken bones, may be carriedout. In such cases, solid matter, which may chiefly consist of cleansedbones, can soon accumulate at the bottom of the inactivation area, andthe fatty fraction of the liquid phase will gather at the top of theinactivation reactor.

Depending upon the temperature at which the inactivation area isoperated, the exposure of the fatty fraction liquid phase and/or solidmatter to the heated walls of the inactivation area may cause depositsor residue to form on the inner surface of the inactivation area. Overtime, these residues and deposits may increase, and thereby requiringadditional heat to be provided to the inactivation area in order tomaintain a desired temperature to inactivate the enzymes. Eventually,the inactivation area may be shut down so that the inner surface can becleaned to remove excess residue and deposits. In one embodiment awiper, blade, or the like may be used to periodically skim or clean theinner surface of the inactivation area, thereby allowing it to remain inservice for a longer period between shut-down and cleaning.Alternatively, a gentle mixer or stirrer may be used to create fluidflow of reaction mixture that contacts heated surfaces of theinactivation area.

If an auger or screw is provided in the inactivation area, onealternative embodiment provides that the auger or screw may be heated sothat heat is distributed more evenly or efficiently into the reactionmixture. In this embodiment, the overall operating temperature of theheated surfaces may be lowered from the ranges provided above by about3° C. or more, or more preferably by about 5° C. or more. Lowering thetemperature of the heated surfaces may reduce or eliminate the build upof deposits or residue because of better or more efficient distributionof heat to the reaction mixture.

In one embodiment, the inactivation reactor at its exit end comprises atleast one outlet for the separate removal of the solid matter component,such as bones and the like, to the extent necessary and at the desiredrate. The removal of the solid matter component may be continuous orintermittent and advantageously avoids the accumulation of a voluminoussolid matter that unnecessarily takes up space in the inactivation area,thereby preventing or delaying the additional or continuous feeding ofnew reaction mixture at the entry end of the inactivation area. The atleast one outlet for the solid matter component may be substantiallypositioned at the same level or below the level of the solid matterlayer where it is located in the inactivation area, or may simplycomprise a transporter (e.g., screw, conveyor, belt, etc.) for the bonesand other solid components that are located at the bottom of theinactivation area.

In one advantageous embodiment, a single screw is employed in theinactivation chamber. At the exit end of the chamber, there is providedan opening where the inactivated reaction mixture (solid component andliquid component) is emptied through a tube, passage or conduit by meansof a large, slow-turning pump that avoids or minimizes emulsion (e.g.,an Archimedes pump, a single or double screw pump, or the like), ontoone or more screens/filters which substantially removes the largerpieces in the solid component (e.g., bone) above a predetermined filtermesh size.

As used herein, “mesh size” refers to, for example, the number of holesper square inch in a screen. In embodiments where more than one filteror screen is utilized, each filter or screen may have varying mesh sizesso that, for example, the first filter or screen that contacts theinactivated reaction mixture has the largest mesh size, and the meshsize gradually decreases in each subsequent filter or mesh that thereaction mixture contacts. Such variance in mesh size in this multiplefilter or screen configuration ensures that the largest solids areseparated early on while the smaller mesh size filters or screenseffectively separate the smaller-sized solids. Typically, the mesh sizeis from about 1 to about 200 mesh, where particles pass through a screenhaving between 1 hole and 200 holes per square inch. Also encompassedare screens having mesh sizes from about 5 mesh to about 150 mesh, fromabout 20 mesh to about 100 mesh and from about 30 mesh to about 80 mesh.

The liquid phase, including soluble and insoluble particulates, thatpasses through the filter or screen is pumped to a liquid separator,such as a tricanter (also called a three phase separator), whichfacilitates the separation of a fat or lipid component, an aqueouscomponent comprising dissolved proteins, peptides and amino acids, andan aqueous component comprising undissolved proteins, peptides and aminoacids. The pump preferably used in this embodiment is a high capacitypump with slow moving parts in order to avoid creating emulsions.However, only a fixed volume goes to the tricanter so that any volume inexcess of the fixed volume is returned to the inactivation area (e.g.,via an overflow return). Typically, the fixed volume of the tricanter isdetermined by the maximum volume of liquid the tricanter can hold.

When the inactivation reactor has at least one or more additionaloutlets for the removal of the liquid phase, positioned at a distancefrom the outlet for the solid matter phase, the liquid component mayadvantageously be discharged freely, independently of how and when andin what quantity the solid matter phase is discharged. As describedabove, the distance between the outlet for the one or more additionalliquid component and the outlet for the solid component is sufficient toavoid or minimize mixing of the solid components with the liquid-onlycomponents.

In other embodiments, the inactivation area can be provided with one ormore feeder screws for the purpose of shifting or conveying the solidmatter component and/or the liquid component, respectively, through theinactivation area in the direction of the respective outlets. Thisensures in a simple manner that the reaction mixture (now comprisingprimarily solid matter, and liquid, which comprises hydrolysis product)does not accumulate in the inactivation reactor and prevent addition ofnew reaction mixture for inactivation.

In addition, any of the feeder screws described herein can be fittedwith scoops, spatulas, ledges, or sheets arranged along the periphery ofthe threads in order thereby to ensure reliable transport or conveyanceof raw material, reaction mixture or inactivated reaction mixture in therespective areas (i.e., the collection area, the hydrolysis area, theinactivation area and the separation area). One illustration of a feederscrew having this configuration is provided in FIG. 8. As shown, ascoop, spatula, ledge, or sheet may be disposed at or near the outermostedge of the screw or auger. As the screw or auger rotates, these devicesgently slide under solid matter resting on the bottom surface or floorand gently lifts the solid matter. As the screw or auger continues torotate or turn, eventually the solid matter slides and falls off of thescoop, spatula, ledge or sheet. In this manner, the screw or auger canprovide gentle mixing of solid matter that might otherwise entrapportions of the reaction mixture that could be hydrolyzed.

And as described above for the collection and hydrolysis areas, theinactivation area may be designed to maintain a low level of emulsion inthe reaction mixture. For example, the inactivation area may comprise aconveyance mechanism (e.g., screw or paddle or spatula) that conveys theinactivated reaction mixture at a rate that avoids or minimizesemulsification. Emulsion control or maintenance and/or demulsificationcan be achieved by the methods described above for the collection and/orhydrolysis areas. Where screws or other devices are used to transportand mix the reaction mixture in the inactivation section, such devicesmay be configured to avoid vigorous mixing that can result in additionalemulsification.

E. The Separation Area

The apparatuses or methods of this disclosure can include one or moreseparation areas. The separation area simply connotes the place, e.g.,an assembly, section, stage or separate housing, chamber, reactor orunit, where the inactivated reaction mixture is separated into itsconstituent components after inactivation in the inactivation area. Theseparation area can be in direct or indirect communication with theinactivation area, and located either nearby or remote from theinactivation area. Thus, the separation area can be directly connected,or connected through one or more intermediate sections, connections orconduits. Alternatively, the separation area can be remotely locatedfrom the inactivation area and the inactivated reaction mixture simplytransported to the separation area.

The separation area is capable of separating at least a portion of theinactivated reaction mixture into two or more constituent componentsusing any number of separation means or systems, as discussed below.Separation can be conducted in sequence, e.g., first solids may beseparated from the liquid, and then the different components of thesolid and/or liquid may be separated. Combinations of separationprocedures likely will be employed (e.g., pumping off of the fattylayer, screen filter separation of liquid from solids, andcentrifugation, decanting and/or tricanting) may be used to achieve thedesired separation and products. Separation also can be conducted inparallel or concurrently, e.g., solids and liquids can be separated offfrom the reaction mixture at the same time, and then further separated.Different liquids, including e.g., the fat layer, the aqueous layercomprising dissolved proteins, peptides and amino acids, and the aqueouslayer comprising undissolved proteins peptides and amino acids can beremoved or separated by, for example, pumping, centrifugation,decanting, tricanting or any combination thereof concurrently and/orsequentially.

In one embodiment, separate outlets for different components of thereaction mixture are found in the separation area. One or more outletsmay be present in the separation area to remove the solid component andmay be subjected to further processing as described herein, for example,processing the solid component into bone meal. One or more outlets maybe present in the separation area to remove the liquid component, whichmay be further separated into the various fractions of the liquidcomponent, such as a fat or lipid component, an aqueous componentcomprising dissolved proteins, peptides and amino acids, and an aqueouscomponent comprising undissolved proteins, peptides and amino acids. Forexample, the outlet for one or more liquid components may appropriatelybe positioned in a plane, which is parallel to and intersecting therespective liquid component and at a distance from the outlet for thesolid matter phase sufficient to avoid or minimize mixing of the solidcomponent with the liquid component. Thus, for example, a solid matterphase is discharged from one outlet into a container or chamber in theseparation area that receives the solid matter, while a liquid componentis discharged from another outlet spaced apart from the outlet for thesolid matter.

In another embodiment, a filter or screen, as described above, isemployed to filter the reaction mixture and separate, for example, solidcomponent from liquid component. In such embodiments, reaction mixturecomprising both a solid component and a liquid component are contactedwith the filter screen and the solids taken off above the filter andliquid filtrate taken off below.

In yet another embodiment, the solid component of the inactivatedreaction mixture can be separated from the liquid component by any ofthe methods described above or by other filtration methods. Meanwhile,the liquid component can be pumped, flushed, spilled, piped, orotherwise transported to one ore more decanter or tricanter centrifuges,which spins or otherwise separates the liquid component into separateconstituent components (i.e., fat or lipid component) and/or aqueouscomponent comprising dissolved proteins, peptides and amino acids,and/or aqueous component comprising undissolved proteins, peptides andamino acids.

F. Batch and Continuous Operation

The apparatuses and methods described herein, or areas thereof, may beused in batch process mode. In a batch process, a predetermined amountof raw material is fed through the system and processed before anyadditional raw material is fed into the system.

Embodiments disclosed herein are, with appropriate scale-up, capable ofhydrolyzing two tons, three tons, four tons, or five tons or more of rawmaterial per hour.

Advantageously, however, the apparatuses and methods involve acontinuous process, in which raw material is continuously fed withoutany need for pre-measurement, and the process runs continuously forperiods of up to 1-3 months or longer. Thus, any of the aforementionedareas, apparatus, methods or plants may be configured to continuouslyoperate 24 hours a day for days or weeks at a time withoutinterruptions. Advantageously, the apparatuses and methods areconfigured to provide at least three days of continuous operation, moreadvantageously at least seven days, and more advantageously at least tento thirty days of continuous operation. At some point, the operator mayfind it desirable to stop production and clean the various areas tomaximize the efficiency and capabilities of the system. For example,cleaning the various areas include chemical and/or physical means, suchas scooping or scraping solid matter or residue from the bottom or sidewalls of each respective area, addition of acid or base to dissolvesolid matter or residue, and application of pressurized liquid orsolvent to remove solid matter or residue.

In any of the embodiment described herein, an apparatus or method maycomprise more than one area or section performing a similar or the samefunction in parallel. For example, two or more inactivation areas may beprovided with an apparatus or method so that the apparatus may continueto operate even if one of the inactivation areas is shut down formaintenance or cleaning. Likewise, multiple areas or sections may beused to provide greater adjustability of processing rates under optimumconditions. For instance, two or more smaller tricanters may be used toseparate components more efficiently and/or more quickly than a single,large tricanter. Thus, an apparatus or method that is capable ofprocessing 10 tons or more of raw material per hour may have two or moretricanters capable of processing 5 tons each.

Alternatively, an apparatus or method of the present invention maycombine two, three or more areas or sections within a single housing orassembly. For example, an extended, rotating auger or screw can beprovided within a housing or chamber. As the screw or auger rotates, itadvances the raw material or reaction mixture through the housing orchamber. Different regions of the housing may have different operatingconditions corresponding to the area, section, or stage of thehydrolyzing processes described above. Thus, an initial portion orregion of the housing may be designated as a hydrolysis area having atemperature within a range that is conducive for hydrolysis. A secondportion or region of the housing may be an inactivation area having anelevated temperature that inactivates the enzyme. A third portion orregion of the housing may be at least a portion of a separation areawhere the inactivated reaction mixture is separated into its constituentcomponents. For instance, a portion of the housing may form a screen orplurality of apertures through which the liquid phase may pass.Continued turning of the screw thereafter urges solid matter toward acollection point or subsequent processing area.

G. Emulsion Control

As mentioned above, under certain circumstances, such as when low fatcontent is important for the end product or when high quality oils aredesired, it is desirable to keep as much of the fat component aspossible substantially separated from the aqueous component. Forexample, the fat component may be removed during the process, such asafter inactivation as described above. Alternatively, the fat componentmay be removed prior to inactivation and, if so, is preferably removedand substantially free (i.e., less than 90%, preferably less than 95%,more preferably less than 99%) of the aqueous phase that contains activeenzyme. In another embodiment, the amount of emulsification may becontrolled in the reaction mixture by methods known by one of ordinaryskill in the art. Emulsification causes protein and lipid to bindtogether, and it has been found that, once mixed in the form of anemulsion, it is difficult to later separate the protein and lipidcomponents using centrifugation in a large scale process. Thus, when theprocess causes emulsification due to blending, high sheer forces, or bysome other means, it is difficult to obtain an end product having a fator lipid content below 2-3% from starting raw material that has a fatcontent of 15-25% w.w., as do most raw fish, poultry and meat productsthat have not been preprocessed for fat reduction. It has been found,rather, that yields containing less than 1% fat in dry matter (2-3% fat)from starting raw material containing 15-25% fat are possible in a largescale process if the reaction mixture is conveyed in a manner thatcontrols or limits emulsification to an amount below 10% of the reactionmixture, more preferably below 5% of the reaction mixture, morepreferably below 2% of the reaction mixture, more preferably below 1% ofthe reaction mixture, and most preferably at or below 0.5% of thereaction mixture.

Such emulsion control can be accomplished in various ways, such as byminimization of vigorous mixing and turbulence, as discussed above.Additionally, or alternatively, chemical emulsion control agents and/orphysical or chemical demulsification may be utilized.

The percentage of emulsification in the reaction mixture can bemeasured, for example, by taking a representative sample from thehydrolysis reactor and/or from the inactivation reactor and comparingthe volume of emulsion with the total volume of the reaction mixture orinactivated reaction mixture. The solid matter component is removed fromthe representative sample, and the liquid portion it is centrifuged fora time and spin rate sufficient to separate the fat or lipid componentfrom the remaining aqueous component(s). Centrifugation times can varyfrom about 30 seconds to about 30 minutes, preferably from about 1minute to about 15 minutes, more preferably from about 2 minutes toabout 10 minutes, and most preferably from about 3 minutes to about 5minutes. Again, as described above, all range limits disclosed hereinmay be interchanged to form new ranges. For example, centrifugationtimes of between about 30 seconds and 10 minutes, 1 minute to about 3minutes, and 5 minutes to about 15 minutes are also encompassed.Centrifugation spin rates vary from about 500 rpm to about 10,000 rpm,preferably from about 1000 rpm to about 5,000 rpm, more preferably fromabout 2,000 rpm to about 4,000 rpm and most preferably about 2,500 rpmto about 3,500 rpm. The centrifuge tube is then removed from thecentrifuge and the contents are analyzed. The centrifuge tube cancontain a sediment component or portion of insoluble or undissolvedproteins, peptides and amino acids, an aqueous component or portionabove the sediment portion having dissolved proteins, peptides and aminoacids, an oil or fat component or portion above the aqueous component,and an emulsified component or portion, which comprises an suspension ofoil or fat in water, separating the oil portion from the aqueousportion. The percentage volume of the emulsion portion versus thecombined sediment, aqueous and oil portions represents the percentage byvolume of emulsion in the reaction mixture.

H. The Reaction Mixture and Resulting Hydrolvsate

As mentioned above, the reaction mixture includes protein-containing rawmaterial, enzyme, and water. When certain raw material, such as fish andbone-containing meat, is used, the reaction mixture includes at least asolid matter component and at least one liquid component. If the rawmaterial further contains fat, the liquid in the reaction mixturetypically separates into several distinct components, including, but notlimited to, a fat or lipid liquid component and at least one liquidaqueous component. Thus, the reaction mixture can separate into severaldistinct components including one or more of a solid component, at leastone aqueous liquid component, and fat-containing liquid component.

When fat or lipids are present, it may stratify on top of the aqueousliquid. Thus, a substantial amount of the fat component can settle atthe top of the inactivation area or hydrolysis area and may, if sodesired, be removed or separated through an outlet for the fat componentat the exit end of the inactivation area or hydrolysis area that ispositioned in a plane parallel to and intersecting the fat component.Alternatively, the fat or lipid component may be removed or separated bypumping through one or more conduits present in the hydrolysis area,inactivation area and/or separation area, where it may be furtherseparated by centrifugation and/or decanting, as described herein.Additionally, or in the alternative, the fat or lipid component can beremoved with the aqueous component and separated by centrifugationand/or decanting.

The aqueous liquid component, which can contain partly dissolved aminoacids, peptides and/or proteins, and partly non-dissolved or insolubleamino acids, peptides and/or proteins, or mixtures of these ingredients,as well as fat droplets, may also be independently removed or separatedthrough one or more similarly arranged aqueous component outlet at theexit end of the inactivation area and/or separation. Alternatively, theaqueous liquid component may be removed or separated by pumping throughone or more conduits present in the inactivation area and/or separationarea.

The liquid component also may include non-dissolvable and non-dissolvedingredients, which may exist in a second separate aqueous component,typically found in a layer below the aqueous layer containing thesoluble components. Like the other liquid components, this secondaqueous component may be removed or separated through one or moreseparate outlets at the exit end of the inactivation area where theoutlets are positioned to contact the second aqueous component, oralternatively pumped out through one or more conduits in contact withthe second aqueous component. I. Products Produced

The reaction mixture, including the solid and liquid components, can beextracted and/or separated to yield different useful products using theapparatus and methods described herein. The fat component can beextracted and processed into various useful products, such as, but notlimited to, food additives and other edible oils. The solid mattercomponent can also be extracted and processed into various usefulproducts such as, but not limited to, bone meal and fertilizer. Theliquid component can be further separated into various fractions,including but not limited to a fat or lipid component, an aqueouscomponent containing water soluble proteins, peptides and amino acids,and an aqueous component containing water insoluble and undissolvedproteins, peptides and amino acids. The hydrolysate comprising the watersoluble protein can, depending on the raw material, be high in proteincontent, low in fat content, and have a high digestibility coefficient,which can make it useful in industrial fermentation, or as foodadditive, nutritional supplement, broth, biological culture medium, orfertilizer, among other things.

The coefficient of digestibility or digestibility coefficient can bemeasured in different animals, such as humans, dogs, cats, mink, etc.The digestibility coefficient refers to the proportion of ingestedhydrolysate product that is actually digested and absorbed to serve themetabolic needs of the animal. In one embodiment, digestibility ismeasured in mink. Typically, mink are fed a known amount of hydrolysatethat is extracted from the water-soluble protein fraction, and theirwaste product is analyzed and measured for protein content. The amountof protein absent from the waste product is assumed to have beenabsorbed to serve the metabolic needs of the animal.

Advantageously, the hydrolysate has a digestibility coefficient of atleast about 70%, preferably at least about 80%, more preferably at leastabout 90%, even more preferably at least about 95%, and most preferablyat least about 97%.

Embodiments described herein advantageously provide yields of solubleprotein of at least about 50%, preferably at least about 60%, and morepreferably at least about 70% based on the weight of protein in the rawmaterial. The yield can be measured in various ways, such as by usingthe Kjeldahl method, which is well known in the art, and determines theamount of protein by weight by measuring the amount of nitrogen presentin a sample. Typically in the Kjeldahl method, the total protein byweight of the raw material (using a representative sample) is measuredand compared to the total protein by weight of the soluble protein endproduct (using a representative sample).

An example of yield calculation is as follows: 1000 kg of raw materialis hydrolysed. This raw material contains 20% protein in wet weight(analyzed sample), giving a total of 200 kg protein into the system.This amount gives 300 kg of hydrolysate with 50% dry matter (weighedafter evaporation) with a protein concentration of 88%. This means thatthis fraction contains 132 kg protein, which translates to a yield of66% (150 kg dry matter with 88% protein=132 kg protein, which is 66% ofthe 200 kg protein put into the system).

The hydrolysate obtained from the processes and apparatuses describedherein may refer to the aqueous component following separation,containing soluble proteins, peptides and amino acids. The term“hydrolysate” also may refer to various concentrated solutions of theaqueous component or even to the dry hydrolyzed protein matter, whichcan be obtained from the aqueous component by removal of water. Thehydrolysate will constitute some percentage of the aqueous component asit comes from a separator, e.g., which takes out the fine solids.

In embodiments of this invention, for example, the aqueous component,which may itself be referred to as a hydrolysate, comprises solubleprotein from about 0.1% to about 20%, preferably from about 1% to about15%, more preferably from about 2% to about 12% and even more preferablyfrom about 4% to about 10% and most preferably from about 6% to about 8%D.M. (dry matter) (that is, as measured by dry protein weight based onthe total weight of the aqueous hydrolysate compared to the total weightof soluble protein contained therein after the hydrolysate has beenevaporated).

In an embodiment, the hydrolysate at this time is evaporated so itcontains approximately 50% D.M. and then an acid such as formic acid isadded to provide resistance to microbes and the hydrolysate which maythen be sold as animal feed or as similar products. However, thispercentage can be greater or less depending on the desired dry mattercontent. For example, the hydrolysate can be dried further to a powder(more than 90% D.M.) and in this embodiment an acid need not be added toprovide resistance to microbes.

J. Enzymes

Many different types of enzymes can be used to hydrolyze the rawmaterial. The type of enzyme or mixture of enzymes used will depend onthe raw material that is being hydrolyzed. For example, proteolyticenzymes and endopeptidase and exopeptides mixtures may be used withprotein-containing raw materials, such as fish, poultry, and beef, lamb,and other meats. Proteolytic enzymes (or “proteases”) include Alcalase®,Neutrase®, Protamex®, and mixtures thereof, each of which can beobtained from Novozymes of Denmark. Endopeptidase and exopeptidasemixtures include Flavourzyme® (Novozymes of Denmark). Other proteolyticenzymes that can be used include Pescalase®, made by Gist-brocades ofthe Netherlands, and Promo 31® made by Biocatalysts Ltd. of Wales.Combinations also can be employed, for example, about 300 grams ofAlcalase® and about 900 grams of Neutrase® per ton raw material canprovide acceptable results for farmed Atlantic salmon. Moreover,proteases present in the raw material, for example, fish proteasescontained in the raw material itself may be used. Also naturallyoccurring proteases isolated from mammalian or other species can used.

When raw materials of vegetable origin are used, it may be necessary toadd carbohydrate-splitting enzymes, i.e., carbohydrases, to break downthe carbohydrates in the material as well, various cellulose-,carbohydrase- and gluconase-based enzymes or enzyme combinations, suchas Cellulase 13L (Biocatalysts), can for this embodiment.

The enzyme amounts employed depends on the type and composition of theraw material, as well as the operating parameters (e.g., temperature andrate of hydrolysis) set by the operator. The main guideline is that theamount of enzyme used sufficient to produce the type and amount ofdesired product. In theory, the amount of enzyme used may be determinedbased on the activity of the enzyme and the number of peptide bonds thatare required to be broken, but the practicalities of the operations,including time and temperature, will require some routineexperimentation to determine the point where hydrolysis no longerincreases even with increasing enzyme addition, for a specific enzyme orcombination. Taste of the resulting product also can vary depending onthe enzyme used and may be factored into the decision of what enzyme(s)to use. Typically, information regarding the optimal amount of enzymethat may be used to hydrolize a given amount of raw material, for agiven enzyme, is provided by the manufacturer of the enzyme.

Most enzymes are not active environments above 85° C. or below about 20°C. Thus, the temperature range in the hydrolysis area advantageously ismaintained between about 20° C. and about 85° C., more preferablybetween about 50° C. and about 60° C., and most preferably at about 55°C.

K. The Figures

FIG. 1 illustrates an embodiment of a hydrolysis apparatus (or system orplant) in greater detail. A collection area 10 comprises a raw materialcontainer 12 and a raw material disintegrator 14. The disintegrator may,for instance, be a meat mincer or a blender, in which the raw materialis finely divided and reduced into smaller-sized pieces, typicallybetween about 15 mm to about 50 mm. In one embodiment, the raw materialsize is reduced in a controlled manner to provide raw smaller rawmaterial pieces that is sufficient to substantially avoids or minimizeemulsification. The raw material is then conveyed to one or morehydrolyzers in the hydrolysis area 20, particularly to a tank 22 wherethe raw material is admixed and contacted with partly warm water (e.g.,at a temperature between about 20° C. to about 85° C.) and acontinuously supplied suitable proteolytic enzyme.

Alternatively, the warm water can be added to the raw material prior tobeing conveyed to the tank 22. One advantage of adding the warm waterbefore the raw material reaches the tank 22 is that, especially duringwinter or with raw material preserved in a cold or frozen environment,the raw material can be cold and the water added can be hot, preferablyclose to 100° C., so that the mixture of cold raw material and hot waterachieves an equilibrium temperature of approximately 50° C. to 60° C.,which is the optimal temperature range for effective enzyme action. Ifthe water is added to the raw material in the tank 22, in the collectionarea 10, or even mixed with the raw material before it is introducedinto the collection area 1, the mixture of cold raw material and hotwater will have ample time to achieve the desired equilibriumtemperature of approximately 50° C. to 60° C., before the enzyme isadded. The enzyme can be added any time after the desired temperature isachieved, either in the collection area 10, and/or in the hydrolysisarea 20. Thus, the average temperature in the collection areaadvantageously will range between 5° C. (temperature of cold rawmaterial) and 60° C. (temperature of cold raw material and water afterreaching equilibrium).

In the embodiment of FIG. 1, the reaction mixture of disintegrated rawmaterial, enzyme and water is fed into a hydrolysis reactor 24 and, bymeans of a first feeder screw (not shown) of the same diameter as thehydrolysis reactor 24, passes through it at a feeder rate so determinedas to allow the enzymes to have hydrolyzed the greater part of the rawmaterial when it has reached the exit from the hydrolysis reactor 24.The reaction mixture is kept at the optimal hydrolysis temperatureappropriate for the enzyme, so that the meat portion is dissolved,leaving the cleansed bones at the bottom of the hydrolysis reactor 24.

The feeder rate is determined by taking into account the dimensions ofthe hydrolysis reactor 24 and the supply rate of the reaction mixture,as well as the exit rate of the reaction mixture from the hydrolysisreactor 24 into an inactivation area 30. The feed rate can be controlledby a person or by a computer that monitors the various parameters of thehydrolysis area and modifies the feed rate to achieve desired results.

The inactivation area 30 comprises an inactivation reactor 32, with anentry end 33 having an inlet and an exit end 34 having one or moreoutlets 34 and 36. The inactivation reactor can be any shape or size andpreferably is a tube reactor surrounded by a heating mantle 37. Thecross section shape of the inactivation reactor can also be, forexample, U-shaped, V-shaped or triangular, a parallelogram (e.g.,square, rectangular, diamond-shaped etc,), oval and the like. Admixingof reaction mixture with the heat released from the heating mantle 37,in order to denature the enzyme present in the reaction mixture, as wellas other ingredients of protein origin, takes place by means of arotating second feeder screw (not shown) of a diameter smaller than theinactivation reactor 32 and positioned at a distance from the bottom ofthe inactivation reactor 32. The second feeder screw serves, partly bymeans of its rotation, to conduct heat from the heating mantle down intothe reaction mixture, and partly to shift the mixture onward towards theexit end 34 of the inactivation reactor 32. The feeder screws, as wellas the rate of egress of the various components, can be controlled by aperson or by a computer that monitors the various parameters of theinactivation area and modifies the different parameters, such asresidence time and heat, to achieve desired results.

At the exit end 34 of the inactivation reactor, substantially allenzymatic activity has stopped, at which point protein and peptides havebeen denatured by heat and may exist either as water-soluble orwater-insoluble ingredients of protein origin. The originally fed rawmaterial has, at this stage of the method, been substantiallytransformed into a solid component 38 and a liquid component 39. Thesolid component 38, primarily comprising the cleansed bones and/orscales, is discharged through the outlet 35 in the exit end 34 of theinactivation reactor 32 and, after drying, can be processed into bonemeal or fertilizer.

The liquid component 39, comprising fat and the aforementionedcomponents of protein origin, is let out through the outlet 36 in theexit end 34. In some embodiments, it may be preferable to homogenize ormix the liquid layer 39, while in other cases, mixing or homogenizationwill not be beneficial. Advantageously, any such mixing orhomogenization will not result in additional emulsification. In eithercase, the liquid component 39 is conveyed to a final processing orseparation area 40. In FIG. 1, the final separation area 40 comprises adecanter or tricanter 42 that may be used to fractionate the liquidcomponent into a fat fraction 44, a fraction comprising water-solubleingredients of protein origin 46, and a fraction comprisingwater-insoluble ingredients of protein origin 48.

The composition of the continuously fed raw material may varyconsiderably, and the size and the extent of the individual phases andfractions may therefore also vary considerably. Consequently, in somesituations and for some raw materials it may be difficult to arrangeseparate outlets for the fractions of the liquid layer sufficientlyprecisely. Although it may not always be a problem, there can be withsome raw materials a risk that, for instance, the fat component and theaqueous component contaminate each other and even clog their respectiveoutlets. This can make it difficult to discharge the pure separatedproduct phases and fractions continuously from the exit end 34 of theinactivation reactor 32.

Also, it may be undesirable to have the continuously rotating first andsecond feeder screws to continue to push material towards potentiallyclogged outlets. There can be a risk, in these instances, of theinactivation reactor 32 filling to a capacity that prevents the feederscrews from functioning optimally. The pressure forces upon the reactorwalls and upon joints in the pipelines can increase enormously with theensuing risk of leaks or explosions. To prevent this, the plant can bestopped and cleaned occasionally.

In those cases where homogenization is preferred, the liquid componentcan optionally be homogenized with a blender impeller 50, an agitator, acirculation pump, which keeps the suspension circulated andsubstantially uniform or homogenous, as shown in the inactivationreactor 332 in FIG. 3, or the like. The blender impeller 50, forexample, can be positioned in the inactivation reactor 32 in connectionwith the outlet 36 for the homogenized liquid component. Hereinafter theterm “homogenized liquid component” will be applied in describing theliquid component's homogenous suspension of fat and aqueous components.The blender impeller 50 is only required if homogenization is preferred,and if homogenization is not preferred, then the inactivation reactor 32can be provided without a blender impeller 50 or the blender impeller 50can simply be turned off. The blender impeller 50 homogenizes the liquidcomponent and suspended ingredients in order to form a homogenizedliquid component, so that this homogenized liquid component or parts ofit does not accumulate in front of and block the outlet 36. Withhomogenization, adapted to the type and composition of the raw material,the heat-treated liquid and/or suspended reaction mixture is dischargedcontinuously and without interruption through the outlet 36 in the exitend 34 of the inactivation reactor 32. Thus, optionally a liquidcomponent rich in fat can be admixed during vigorous homogenization.

As discussed above, dissolved and non-dissolved ingredients in the formof proteins, amino acids and peptides, resulting from or remaining afterthe hydrolysis area 20, and the subsequent denaturing and inactivationof these by means of suitable agents produced in the inactivation area30, may be mixed to form a substantially homogenous suspension, whichmay readily and speedily be let out continuously and separated from thesolid matter component 38. This embodiment makes no requirements as tothe composition of the raw material and is less sensitive to thepositioning of the outlets from the inactivation reactor 32.

The homogenized liquid component is next conveyed to a separation area50. The separation assembly includes a continuously functioning decanteror tricanter 42 for final separation.

In the instance where a decanter is used, the homogenized liquidcomponent is fractioned into a fat fraction and an aqueous fraction withsoluble and insoluble ingredients.

In the instance where a tricanter is used, the aforementionedhomogenized liquid component is fractioned into a fat fraction 44, anaqueous fraction with water-soluble ingredients 46, and a fraction withwater-insoluble ingredients 48, preferably in the form of denaturedproteins and peptides which are generally non-dissolvable or heavilynon-dissolvable in water, as a result of their hydrophobic side chainsexposed in the denaturing.

The end fractions obtained further may be purified or used directly as anutrition supplement. Furthermore, the soluble protein fraction has beenfound to be a valuable source of proteins, peptides and amino acids foruse in industrial fermentation, fertilizers, animal feeds, culturemedium, and nutritional and food supplements. It has been found that thehydrolysate extracted from the protein soluble fraction has a biologicaldigestibility coefficient of 90% or above, and more specifically 95-97%.

Thus, it is possible to utilize many different types of waste productsfrom the food industry, which would otherwise have to be incinerated tobe eliminated. Accordingly, such waste products may now become avaluable resource in the food industry.

For instance, essential fatty acids and oils, such as omega-3 fattyacids, may be extracted from the fat fraction 44. A solid component 38in the form of cleansed bones may be used in the production of bone mealfor use in animal feed. Fractions in which the content of dry matterstems from proteins, may be used in enriching foods by proteins,peptides or amino acids. A fraction without bitter hydrophobic aminoacids will in particular be preferred for foods for humans.Alternatively, the protein fraction may be used for animal feed.

In yet another embodiment, in which a low fat content in the end productis desired, the fat component or part of the fat component can bewithdrawn or removed from the inactivation reactor 8 batch wise orcontinuously from the top of the inactivation reactor 8 separately fromthe aqueous component. The remaining aqueous component may contain smallamounts of fat droplets, but for the most part will comprisewater-soluble and water-insoluble ingredients. In the case of some rawmaterials, the resulting reaction mixture can be discharged asindependent fractions through independent outlets in the exit end of theinactivation reactor 32. Otherwise, the fractions can be separated inthe separation area 40.

FIG. 2 shows an additional embodiment for the hydrolysis described withrespect to FIG. 1. In this embodiment a preparation section 200 has afurther section 216 interposed between a raw material container 212 anda disintegrator 214, for the purpose of removing metal containingingredients, such as fishing hooks, shots and broken knife edges, fromthe raw material. In the example shown, the section 216 has a magnet218.

A hydrolysis section 220 receives raw material from the preparationsection 200 and hydrolyzes it. The hydrolysis section includes a tank222 where the raw material is mixed with warm water and enzyme. Ahydrolysis reactor 224 receives the mixture of raw material, enzyme andwater from the tank 222 and conveys it onward to an inactivation section230.

The inactivation section includes an inactivation reactor 232 thatreceives the hydrolyzed or partly hydrolyzed reaction mixture through aninlet located at the entry end 233. The inactivation reactor includes aheating mantle 237 and outlets 235 and 236 in its exit end 234. Theenzyme in the reaction mixture is inactivated in the inactivationreactor 232 and a solid component 238 of the reaction mixture isdischarged through a first outlet 235, while a liquid component 239 isdischarged from a second outlet 236 separate from the first outlet 235and positioned at a distance from the first outlet 235. A blenderimpeller 250 operating within the inactivation reactor 232 can also beincluded to homogenize the reaction mixture.

A separation area or section 240 receives the liquid component 239 intoa decanter tricanter, which centrifuges it into three fractions: a fatfraction 244; a liquid fraction comprising water soluble ingredients ofprotein origin 246; and a fraction comprising water-insolubleingredients of protein origin 248.

FIG. 3 shows an additional embodiment for hydrolysis. In thisembodiment, the inactivation reactor 332 has no blender impeller.Instead the liquid phase is kept in circulation in the inactivationreactor. The circulation may for instance be maintained by a circulationpump, which is not shown.

As before, a collection area 300 has a raw material container 312, a rawmaterial disintegrator 314, and a further section 316 interposed betweenthe raw material container 312 and disintegrator 314, for the purpose ofremoving metal containing ingredients, such as fishing hooks, shots andbroken knife edges, from the raw material. In the example shown, thesection 316 has a magnet 318.

A hydrolysis section 320 receives raw material from the preparationsection 300 and hydrolyzes it. The hydrolysis section includes a tank322 where the raw material is mixed with warm water and enzyme. Ahydrolysis reactor 324 receives the mixture of raw material, enzyme andwater from the tank 322 and conveys it onward to an inactivation section330.

The inactivation section includes an inactivation reactor 332 thatreceives the hydrolyzed or partly hydrolyzed reaction mixture through aninlet in its entry end 333. The inactivation reactor includes a heatingmantle 337 and outlets 335 and 336 in its exit end 334. The enzyme inthe reaction mixture is inactivated in the inactivation reactor 332 anda solid component 338 of the reaction mixture is discharged through afirst outlet 335, while a liquid component 339 is discharged from asecond outlet 336 separate from the first outlet 335 and positioned at adistance from the first outlet 335.

A separation area or section 340 receives the liquid component 339 intoa decanter or tricanter 342, which centrifuges it into three fractions:a fat fraction 344; a liquid fraction comprising water solubleingredients of protein origin 346; and a fraction comprisingwater-insoluble ingredients of protein origin 348.

With respect to any one of the embodiments described herein, thereaction mixture is kept at the optimal hydrolysis temperatureappropriate for the enzyme, so that the meat portion is dissolved,leaving the cleansed bones at the bottom of the hydrolysis reactor. Thefeeder rate is determined by taking into account various parameters.such as the temperature and particular enzymes used, the dimensions ofthe hydrolysis reactor and the supply rate of the reaction mixture, aswell as the exit rate of the reaction mixture from the hydrolysisreactor.

FIG. 4 shows a schematic cross section of a hydrolysis reactor 424according to an embodiment of the invention. A reaction mixture (e.g.,having a temperature of between about 20° C. and 85° C. and preferable50° C.-60° C. and more preferable about 50° C.) of raw material, such ascomminuted fish parts, enzyme and water, is added through the inlet end409 of the hydrolysis reactor 424 as shown by the arrow A. Thehydrolysis reactor 424 can be designed with a first feeder screw 470with threads 474 of approximately the same diameter as the innerdiameter of the hydrolysis reactor 424. Each thread 470 can include ascoop 472 located at the periphery of the screw for mixing and carryingthe reaction mixture towards the exit 480 of the hydrolysis reactor 424.In a first period of time, the first feeder screw 4700 shifts thereaction mixture a distance “a” in the direction of the exit 480. In asubsequent second period of time, the rotation direction of the firstfeeder screw 470 is reversed, thereby pulling the reaction mixture adistance “b” which is shorter than the distance “a”, back towards theinlet end 409 of the hydrolysis reactor 424. The reversing movementprovides optimal hydrolysis conditions and shifts the increasinglyhydrolyzed reaction mixture continuously onward towards the exit 480 andover into the inactivation reactor 432, as shown by the arrow B. Thehydrolysis reactor 424 can be horizontally oriented as shown, verticalor at an angle from between about 1° to 89° (not shown). If verticallyoriented, the input end can be above the output end, such that thereaction mixture is assisted toward the output end by gravity.Alternatively, the output end can be above the input end, such that thereaction mixture is advanced toward the output end against gravity.

The inactivation reactor 432 is arranged with second and third feederscrews 482 and 488, both of which may, in a manner similar to the firstfeeder screw 470, optionally be designed with scoops or sheets 472 forcarrying the reaction mixture. The second feeder screw 482 typicallymakes the same reversing movement in the inactivation reactor 432 asdoes the first feeder screw 470 in the hydrolysis reactor 424. Thediameter of the second feeder screw 482 is smaller than the diameter ofthe inactivation reactor 432, to allow for room so that the third feederscrew 488 can shift a solid matter component in the form of cleansedbones and other solid ingredients out through the outlet 435 in the exitend 434 of the inactivation reactor 432. The inactivation reactor issurrounded by a heating mantle 437, maintaining a temperature suitableto inactivate the hydrolysis enzyme, for example, of between about 85°C. and about 100° C., preferably about 95° C. It has been found thatseparation of the different components is best achieved when thereaction mixture is maintained within this temperature range andpreferably at about 95° C.

By combining and adapting the operational parameters, such as thetemperature, length of the reactors 424, 432 and the amount of rawmaterial in it, to the type, the quantity and the concentration or theenzyme in combination with the rate of the feeder screws 470, 482, 488and the number and the length “a” and “b” of the movements of the feederscrews, it is possible to optimize the holding time in the reactors 424,432 and thus the reaction and inactivation time. The optimal operationparameters by means of which it is possible to control the proportion ofamino acids which lend a bitter flavor to the hydrolysate, and keep itas low as possible, can be determined empirically or by theoreticaldetermination, optionally followed by control measuring.

An outlet for a phase or fraction is, as mentioned above, arranged inthe exit end of the inactivation reactor 432, emerging from a planewhich is parallel to and intersecting a plane in the inactivationreactor 432 where the phase or fraction adjusts itself. An outletextends across a part of the thickness of that phase or fraction,thereby ensuring rapid continuous outlet of phases and fractions withoutthem contaminating each other.

Variations of the foregoing apparatus and method can be envisaged. Forexample, a fat component may be collected and utilized independently orre-admixed with the aqueous component, before the mixture ispost-processed in the final treatment section.

Alternatively, the second feeder screw 482 may be given a diameter solarge (not shown) that it may be used simultaneously for carrying thesolid phase onward towards the outlet 435. In another embodiment (notshown), the second feeder screw 482 can be given a diameter, which fillsthe entire inactivation reactor 432, and a length, which allows spacefor a comparatively short third feeder screw 488.

In FIG. 4, the third feeder screw 488 is shown as being positioned inits entirety along the bottom. It may, however, be appropriate to let atleast part of the third feeder screw 488 rise above the liquid componentin order to sift it off before the solid matter component is let outfrom the inactivation reactor 432. In such an embodiment (not shown) theoutlet for the solid matter component would be situated above the outletfor the liquid component.

Turning to FIG. 5, a system is depicted for controlling the level ofemulsification in the reaction mixture. A preparation area 500 has a rawmaterial container 512 and a raw material disintegrator 514. Thedisintegrator 514 may for instance be a meat mincer or a blender bymeans of which the raw material is finely divided into smalleringredients in a gentle manner that substantially avoids emulsification.The raw material is then carried onwards to a hydrolyser in thehydrolysis area 520. In the hydrolysis area 520 the finely divided rawmaterial is conveyed onwards to a tank 522 where it is admixed withpartly warm water and a continuously supplied suitable proteolyticenzyme. The reaction mixture of disintegrated raw material, enzyme, andwater is fed into a hydrolysis reactor 524 and, by means of a firstfeeder screw (not shown) of, for example, approximately the samediameter as the hydrolysis reactor 524, passes through it at a feederrate so determined as to allow the enzymes to have hydrolyzed thegreater part of the raw material when it has reached the exit from thehydrolysis reactor 524. The feeder screw rate should also be set so asto minimize emulsification, with separate fat and aqueous componentsforming with limited emulsion. The aqueous component may have fatdroplets dispersed through it, but emulsification can be controlled.Only 5%, and preferably only 2%, and preferably less than 2%, and verypreferably less than 1%, and most preferably less than or equal to about0.5% of the reaction mixture is emulsified. The feeder screw can operatewith low sheer forces with a substantially slow rotation to controlemulsification. In this manner, the reaction mixture is conveyed slowly,such that emulsification is controlled.

If the percentage of emulsification is above a desirable amount, such as0.5%, then the hydrolysis reaction can be modified to reduce thepercentage of emulsification to acceptable levels. Emulsification can becontrolled in various ways, such as chemically (chemical emulsioncontrol and/or demulsification) or physically (physical emulsion controland/or demulsification).

In one embodiment (not shown), an optional pump can draw a portion ofthe fat component formed in the reaction mixture away from thehydrolysis reactor 524 and deposit the fat in a fat holding container570. The fat from the fat holding container 570 can then be processedinto various end products. This modified embodiment also improves thequality of the recovered fat, because the fat is not exposed to the highheat levels found in the inactivation area 530. Alternatively, oradditionally, fat can be removed from the inactivation area.

Alternatively, as shown in FIG. 5, the fat from the fat holdingcontainer 570 can be transferred to the separation area 540 or directlyto the decanter or tricanter 542, for further processing in conjunctionwith the aqueous component.

Meanwhile, the remainder of the reaction mixture contains mostly a solidmatter component and an aqueous component, with the aqueous componentadvantageously having low or substantially no emulsion. The reactionmixture is conveyed from the hydrolysis reactor 524 to the inactivationarea 530 using either a single conveyor screw configuration or a doubleconveyor screw configuration as described above with respect to FIG. 4.In the inactivation area 530, the reaction mixture enters theinactivation reactor 532 where the enzymes in the reaction mixture areinactivated as explained above. The inactivation reactor 532 includesonly one outlet 535 for both the aqueous component and the solid mattercomponent, which will be discharged from the outlet together. Theinactivation reactor 532 can also include a mild agitator 550 thatrotates in the reverse direction to prevent solid matter from cloggingthe outlet 535. The mild agitator 550 lifts solid matter blocking theoutlet 535 into the reaction mixture and it is discharged in combinationwith the aqueous component. A pump can be used to draw out the reactionmixture and pump it to a filter screen 560 where it is deposited. Thefilter screen 560 filters away the solid matter component and depositsit in a solid matter container 543 associated with the separation area540. The aqueous component is deposited in the decanter or tricanter 542associated with the separation area 540.

FIG. 6 illustrates a filtration system which may be used as describedherein. The reaction mixture includes a fat component 610, an aqueouscomponent 615 and a solid matter component 620 all advancing toward theoutlet 650. As described above, in certain circumstances much of the fatcomponent 610 can be removed from the hydrolysis reactor, but in othercircumstances the fat component 610 will remain, and the aqueouscomponent 615 will also contain some fat droplets unless the rawmaterial is substantially fat free. In any case, the solid matter 620 isagitated by a mild agitator 655 that rotates in a reverse direction withrespect to the outlet 650. This reverse rotation lifts the solid mattersediment forming near the outlet 650 so that the outlet 650 is notblocked by the sediment. A trough 660 adjacent the outlet 650 alsocontrols the amount of outlet 650 blockage, because any sediment notchurned by the mild agitator 655 rests at the bottom of this trough 660and away from the outlet 650. A large, high capacity pump 665 operatingat low speeds pumps the reaction mixture up through pipe 670. A lowspeed, high capacity pump 665 will cause less emulsification than a highspeed pump.

The reaction mixture is pumped toward a nozzle 675 from which thereaction mixture is discharged onto a filter screen 680. The filterscreen 680 is slanted downward and includes a first filtration region682, followed by a nonporous region 684, which is followed by a secondfiltration region 686. The first and second filtration regions 682 and686 are permeable to the fat and liquid forming the fat component 610and the aqueous component 615 but impermeable to the solid matterforming the solid matter component 620. The nonporous region 684 isimpermeable to fat, liquid and solid matter. Beneath the firstfiltration region 682 is a funnel 690 that catches the fat and liquidfiltering through the first filtration region 682. The fat and liquidtend to cool once they have been discharged from the inactivationreactor 632. Therefore, the fat and liquid caught by the funnel is leadto a heat exchanger 692, which heats the mixture back to between about90° C. and about 110° C., more preferably between about 93° C. and about97° C., and most preferably about 95° C. Thus, when the fat and liquidreach the tricanter, the temperature of the mixture in the tricantershould be between about 90° C. and about 110° C., advantageously betweenabout 93° C. and about 97° C., and most advantageously about 95° C. Ithas been found that this increased level of heat tends to optimizeseparation of the fat and aqueous components in the tricanter 642, whereit is centrifuged into three fractions: a fat fraction; an aqueousfraction containing water-soluble protein; and sediment containinginsoluble protein.

A second funnel 695 beneath the second filtration region 686 catches anyremaining fat and liquid and a pump (not shown) pumps it back to eitherthe inactivation reactor 632 for further processing, or back to thehydrolysis reactor (not shown) for further processing. Alternatively,the liquid and fat caught by the second funnel 695 can be pumped to theheat exchanger 692 and deposited into the tricanter 642 (via path 140).Additionally, an overflow return (with or without a pump) may beprovided to return overflow reaction mixture to the inactivation reactor632 or hydrolysis reactor in a similar manner as shown in FIG. 9.Meanwhile, the solid matter rolls down along the filtration screen 680and into a solid matter container 643 for further processing. The solidmatter is largely composed of bones, fish scales, rocks, dirt, sediment,and the like. The filtration screen 680 is capable of separating some ofthe solid matter from the liquid and fat, and preferably substantiallyall of the solid matter from the liquid and fat.

In the tricanter 642, the mixture of fat and liquid is centrifuged toobtain three separate fractions: a fat fraction; an aqueous fractioncontaining water soluble protein; and a sediment containing waterinsoluble protein. A suitable tricanter is made by WestfaliaSurge ofGermany model number CA 501-63-32. The number of suitable rpms and thesuitable amount of material to pass through the tricanter per amount oftime is provided by the manufacturer of the tricanter. For example, 4000rpms and a differential speed of 4.3 can be used. The three fractionscan be placed into separate areas and further processed.

In one embodiment, the aqueous fraction containing the water solubleprotein is further purified by centrifuging in a second centrifuge orseparator for example a GEA Wesffalia Separator AG, model number MSD 90(not shown). This removes any remaining fine particles of insolubleprotein. At this stage, the aqueous fraction is still a clear solutionwith about 8% dry matter. Next, the aqueous fraction containingwater-soluble protein can be dried using an evaporator (not shown) toevaporate water, reducing the solution to 50% dry matter. At this stage,the solution is a syrupy product to which acid can be added forpreservation. The product can be further dried using additional dryingequipment to reduce it to 90-95% dry matter.

According to one embodiment as shown in FIG. 9, filter screen 915(similar to filter screen 680 of FIG. 6) is elevated from fluid level925. By elevating filter screen 915 relative to fluid level 925, apump-free overflow return 905 may be provided, the pump-free overflowreturn 905 being positioned approximately at a bottom portion of filterscreen 915 as indicated by level 925. This configuration eliminates theneed for a pump (e.g., a low speed, high capacity pump) to returnoverflow reaction mixture to the inactivation reactor 632 as shown or tothe hydrolysis reactor. It should be appreciated, however, that a pumpmay be provided for pumping overflow reaction mixture via overflowreturn 905 for some applications.

As with the filter system shown in FIG. 6, a funnel 690 (not shown inFIG. 9) may be provided to catch the fat and liquid filtering throughthe first filtration region 682. The caught material may be pumped to aheat exchanger 692 using a low speed, high capacity pump 945 via pipe935. Additional components, such as funnel 695 shown in FIG. 6, may alsobe provided, as would be readily apparent to one of ordinary skill inthe art after reading this disclosure.

Thus, employing the apparatuses and methods taught herein, it is nowpossible to maintain an even and continuous outlet and flow to thedecanter (even with a highly complex composition of the raw material)which gives a quantity and composition of heat treated hydrolysisproducts.

L. EXAMPLES Example 1

By using a method and system similar to that illustrated in FIG. 1, amixture of waste fish material in the form of bones and fish heads fromcod is gently minced at a rate of 3 tons per hour through an orificewith holes of a diameter of 30 mm. The minced fish mixture is conveyedonward at the same rate to a blender vat where boiling water is added atthe ratio 1:1. At the exit from the blender vat the temperature ismeasured as 55° C. To the hot fish mixture was added 1 g of NovoAlcalase® 2.4 per kg mixture, whereafter enzyme and fish mixture wascarried onward to an 8 m long tube-shaped hydrolysis reactor, which hada diameter of 0.9 m. In the hydrolysis reactor the fish mixture withenzyme was slowly carried forward in the longitudinal direction of thetube towards the exit from the hydrolysis reactor by a feeder screw withthreads, which have a pitch of 50%. Each thread was along its peripheryequipped with sheets of a size of 200 mm×200 mm×300 mm. The passage ofthe hydrolysis reactor took 40 minutes, and the temperature of themixture of fish waste and enzyme is measured at the exit of thehydrolysis reactor as 50° C.

The hydrolyzed mixture was conveyed onward to the inactivation reactorwhere the Alkalase® and the natural fish enzymes were inactivated, andproteins and peptides were denatured by heating by means of asurrounding steam mantle which maintained a constant temperature ofabout 120° C. The content of the inactivation reactor was forced onwardtowards the outlets in it by means of a feeder screw, with threads witha 50% pitch and scoops along the periphery of each thread. Halfwaythrough the inactivation tank the temperature of the mixture wasmeasured as 95° C. or higher. The liquid phase was homogenized with apowerful agitator until visible homogenizing was observed, and the solidphase in the form of cleansed bones was continuously removed from thebottom of the inactivation reactor by a feeder screw. The liquid phasecomprised fat, oil, fatty acids, protein, peptides of varying length,amino acids, and water. The homogenized liquid phase is carried onwardto a tricanter where it was split into three fractions, a fat fraction,an aqueous fraction with soluble parts, and an aqueous fraction withnondissolvable parts.

The centrifuging in the tricanter resulted in a 2 percent fattyfraction, 80 percent aqueous fraction with soluble in gradients fromproteins, and 18 percent aqueous fraction with non-dissolvableingredients proteins. Control readings of the composition of the aqueousfraction with soluble ingredients showed this to have a composition of 5percent protein, 0.003 percent fat, and the remainder water. Controlreadings of the composition of the aqueous phase with non-solubleingredients showed its composition to be 7 percent protein, 0.5 percentfat, and the remainder water.

The aqueous protein fractions obtained will have a pleasant flavor ofcod and may be used as the basis for fish sauces and soups, or as anadditive to products of fish meat. The bones from the solid phase may,following drying, be ground into bone meal. The fat fraction has a highcontent of saturated fatty acids and may be used in health foodproducts.

Example 2

The method and apparatus used was similar to that of Example 1, but theraw material was the carcass from boned chickens. The agitation and theadmixing in the hydrolysis reactor were furthered by firstly letting thefeeder screw in the hydrolysis reactor rotate clockwise for a periodallowing the chicken mixture with enzyme to be pulled back by 0.2 m inthe longitudinal direction of the hydrolysis reactor. The fat fractionin the liquid phase was let out separately at the upper edge of theinactivation reactor, one meter before the agitator by means of adiaphragm pump. The fat fraction is pumped onward to the decanter where,before being added to it, is being admixed with the liquid phase fromthe inactivation tank.

The centrifuging in the tricanter resulted in 10 percent fatty fraction,70 percent aqueous fraction with soluble ingredients from proteins, and20 percent aqueous fraction with non-dissolvable ingredients proteins.Control measurings of the composition of the aqueous fraction withsoluble ingredients showed its composition to be 6 percent protein,0.004 percent fat and the remainder water. Control measurings of theaqueous fraction with non-dissolvable ingredients showed its compositionto be 9 percent protein, 0.5 percent fat, and the remainder water.

The aqueous fraction with non-dissolvable ingredients from proteins maybe used as a basis for soups or sauces or as an additive to meatproducts. The aqueous fraction with non-dissolvable ingredients fromproteins may be admixed with meat products, such as minced meat,sausages and luncheon meat. The bones from the solid phase may be groundinto bone meal after having first been dried.

The liquid phase is typically separated into a fatty fraction and one ormore aqueous fractions. The non-dissolvable denatured aqueous proteinfraction has a specific gravity different from the soluble denaturedprotein fraction, and these two fractions will therefore theoreticallybe separated from each other to such a degree that it is possible to letthem out separately for additional post processing. This may be moredifficult in practice, however, with some types of raw material.

Example 3

In this example, the raw material is salmon waste materials, such asfilleted salmon including head. The end product, i.e., hydrolysate, is awhite powder, which is substantially soluble in water at roomtemperature and which contains a mix of proteins, peptides and aminoacids. At room temperature with moderate agitation there is noprecipitation visibly observable to the naked eye. The starting materialhas 15-25% fat, with the remainder being protein and bones. The rawmaterial is hydrolyzed substantially according to the method and systemdescribed with respect to FIG. 1, including controlled emulsificationwithin the hydrolysis reactor and inactivation reactor as discussed withrespect to FIG. 5. Emulsification is limited to two percent of thereaction mixture. Hydrolysis is carried out at a rate of approximatelythree tons per hour of raw material with an additional approximatelythree tons per hour of water. The process is carried out for seventy-twohours without stopping, thus processing approximately 216 tons of rawfish material and 216 tons of water. Continuous hydrolysis could havebeen carried out for a longer duration of time, up to thirty days, butthe reaction is stopped at three days for cleaning of the reactors.

The reaction mixture after hydrolysis and inactivation of enzyme isdeposited in a tricanter and centrifuged to form three fractions: a fatfraction; an aqueous fraction having water soluble protein at roomtemperature; and a sediment formed from insoluble protein. With respectto the water soluble protein, at room temperature with moderateagitation there is no precipitation visibly observable to the naked eye.The solute from the fraction containing water soluble protein isextracted and analyzed. A biochemical analysis of dry product providesthe following data: CHEMICAL CHARACTERISTICS Standard Dry matter 95 ± 2%Protien (N × 6.25) 88 ± 2% Lipid (of DM)  2 ± 1% Ash  5 ± 1% Total aminoacids 81 ± 2% Free amino acids  12 − 14% Peptides < 3000 Da  60 − 63%Chloride (as NaCl)   1.5 ± 0.3%

MICROBIOLOGY Standard Total aerobic microbial <5000/g count SalmonellaAbsence/25 g Yeasts <20/g

TYPICAL AMINO ACID DISTRIBUTION GIVEN AS g/100 g PROTEIN Amino AcidsAbbr. Total (T) Alanine Ala 6.3 Arginine Arg 5.6 Aspartic Acid Asp 6.7Cysteine Cys 0.5 Glutamic Acid Glu 11.1 Glycine Gly 11.7 Histidine His2.8 Isoleucine Ileu 2.3 Leucine Leu 4.1 Lysine Lys 5.2 Methionine Met2.0 Phenylalanine Phe 2.1 Proline Pro 6.0 Serine Ser 3.8 Threonine Thr3.0 Tryptophan Trp 0.5 Tyrosine Tyr 1.5 Valine Val 3.0 OH-proline OHpro3.1

OTHERS Taurine Tau 1.7

MINERALS AND TRACE ELEMENTS Minerals g/kg Ca 1.3 K 20.0 Mg 1.7 Na 22.0 P10.3 Trace minerals mg/kg Cu 1.7 Fe 16.8 I 1.5 Mn 1.1 Se 1.6 Zn 24

The water soluble extract is a white powder that is soluble in water atroom temperature. It has a biological digestibility index of 95-97% astested on mink.

This disclosure has been described above generally and also in terms ofone or more embodiments so that an understanding of the principlesunderlying the apparatuses and processes can be obtained. There are,however, many configurations for hydrolysis of a protein containinganimal or vegetable raw material not specifically described herein butwith which the present disclosure is applicable. The present disclosureshould therefore not be seen as limited to the particular embodimentsdescribed herein, but rather, it should be understood that it has wideapplicability with respect to hydrolysis methods, systems, andapparatus. Moreover, it will be apparent that certain features of eachembodiment can be used in combination with methods, systems, orapparatus illustrated or described in other embodiments. Accordingly,the above description should be construed as illustrative, and not in alimiting sense. All modifications, variations, or equivalentarrangements and implementations that are within the scope of theattached claims should therefore be considered within the scope of theinvention.

As used herein and in the following claims, singular articles, such as“a,” “an,” “the”, “said” and the like, can mean one or more than one,and are not intended in any way to limit the terms that follow to theirsingular form, unless expressly noted otherwise. Unless otherwiseindicated, any claim which contains the word “or” to indicatealternatives shall be satisfied if one, more than one, or all of thealternatives connected by the word “or” are present in an embodimentwhich otherwise meets the limitations of such claim.

The present application claims priority from Danish Patent ApplicationNumber PA 2002 01859, entitled A PLANT AND A METHOD FOR CONTINUOUSHYDROLYSIS OF A PROTEIN CONTAINING ANIMAL OR VEGETABLE RAW MATERIAL ANDAPPLICATION OF THE RESULTING HYDROLYSIS PRODUCTS, filed Dec. 2, 2002,the entirety of which is incorporated herein by reference.

1. An apparatus for the hydrolysis of protein-containing raw material,the apparatus comprising: a hydrolysis area that provides hydrolysis ofsaid raw material by reacting a reaction mixture comprising said rawmaterial and at least one enzyme present in said area, wherein thereaction mixture contains both solids and liquid, and wherein uponhydrolysis, said reaction mixture further comprises hydrolysis product;an inactivation area that receives reaction mixture from the hydrolysisarea and substantially inactivates the enzyme present in the reactionmixture; and a separation area that receives at least a portion of thereaction mixture from the inactivation area and is capable of separatingit into two or more components, including at least one substantiallyliquid component which comprises water-soluble protein.
 2. The apparatusof claim 1, wherein the separation area is capable of separating theportion of the reaction mixture received into said at least onesubstantially liquid component and at least one substantiallysolid-containing component.
 3. The apparatus of claim 1, wherein anyemulsion present in said liquid component is present in an amount at orbelow a predetermined level.
 4. The apparatus of claim 3, wherein thelevel of emulsion present is at or below about 5%.
 5. The apparatus ofclaim 3, wherein the level of emulsion present is at or below about 2%.6. The apparatus of claim 3, wherein the level of emulsion present is ator below about 1%.
 7. The apparatus of claim 3, wherein the level ofemulsion present is at or below about 0.5%.
 8. The apparatus of claim 1,wherein the separation area comprises a slanted filter screen.
 9. Theapparatus of claim 1, further comprising a centrifuge that receives atleast a portion of the liquid component, and which separates the portioninto at least a first fraction comprising water-soluble protein and atleast a second fraction comprising water-insoluble protein.
 10. Theapparatus of claim 1, further comprising at least one pump capable ofpumping oil present in the reaction mixture away from the reactionmixture, or comprises a decanter for decanting oil present in thereaction mixture, or comprises both.
 11. The apparatus of claim 1,wherein the inactivation area comprises at least one outlet for a solidcomponent of the reaction mixture, and at least one outlet for a liquidcomponent of said reaction mixture, said outlet for said liquidcomponent positioned at a distance from the outlet for the solidcomponent sufficient to avoid or minimize mixing of the solid and liquidcomponents.
 12. The apparatus of claim 11, wherein the at least oneoutlet for the liquid component comprises an outlet for an aqueousfraction comprising water-soluble amino acids, proteins, or peptides andwater-insoluble amino acids, proteins, or peptides.
 13. The apparatus ofclaim 1, wherein the hydrolysis area comprises at least one feeder screwfor conveying the reaction mixture through the hydrolysis area.
 14. Theapparatus of claim 1, wherein the hydrolysis area comprises atube-shaped reactor.
 15. The apparatus of claim 1, wherein theinactivation area comprises at least one feeder screw for conveying thereaction mixture through the inactivation area.
 16. The apparatus ofclaim 13, wherein at least one feeder screw rotates clockwise for afirst period of time, and counter-clockwise for a second period of time.17. The apparatus of claim 13, wherein at least one feeder screwcomprises a thread having a scoop or sheet located at its periphery. 18.The apparatus of claim 1, wherein the inactivation reactor comprises anoutlet for discharging at least a portion of the reaction mixture and anagitator adjacent to the outlet that suspends solid matter in thereaction mixture near the outlet.
 19. The apparatus of claim 18, whereinthe agitator comprises a screw that rotates in a reverse direction. 20.The apparatus of claim 1, wherein a pump pumps the reaction mixture outof the inactivation area and toward the separation area, such thatemulsification of liquid in the reaction mixture is maintained at orbelow a predetermined level.
 21. The apparatus of claim 1, furthercomprising a collection area wherein pieces of protein-containing rawmaterial are collected, and wherein said pieces of protein-containingraw material are provided to the hydrolysis area from said collectionarea.
 22. The apparatus of claim 21, wherein the collection areaincludes processing equipment that reduces the size of the pieces of rawmaterial collected.
 23. The apparatus of claim 1, wherein the apparatusis capable of hydrolyzing the raw material at a rate of two tons perhour.
 24. The apparatus of claim 1, wherein the apparatus is capable ofcontinuous hydrolysis for at least seventy-two hours.
 25. The apparatusof claim 1, wherein the hydrolysis area, inactivation area, andseparation area are capable of operating in a continuous non-batch mode.26. The apparatus of claim 1, wherein the apparatus is capable ofproducing a yield of water-soluble protein from the liquid in thereaction mixture of at least about 50 percent by weight of the weight ofprotein contained in the raw material.
 27. The apparatus of claim 1,wherein the apparatus is capable of producing a yield of water-solubleprotein from the liquid in the reaction mixture of at least about 60percent by weight of the weight of protein contained in the rawmaterial.
 28. The apparatus of claim 1, wherein the apparatus is capableof producing a yield of water-soluble protein from the liquid in thereaction mixture of at least about 70 percent by weight of the weight ofprotein contained in the raw material.
 29. The apparatus of claim 1,wherein the apparatus is capable of producing a yield of water-solubleprotein from the liquid in the reaction mixture of about 70 percent byweight of the weight of protein contained in the raw material.
 30. Amethod for the hydrolysis of protein-containing raw material comprisingusing the apparatus of claim 1 to hydrolyze said raw material.
 31. Amethod for the hydrolysis of protein-containing raw material, the methodcomprising: hydrolyzing, in a hydrolysis area, a reaction mixturecomprising the raw material and an enzyme capable of hydrolyzing theprotein in said raw material, wherein the reaction mixture contains bothsolids and liquid, and wherein upon hydrolysis the reaction mixturefurther comprises hydrolysis product; inactivating, in an inactivationarea, enzyme contained in the reaction mixture; and separating at leasta portion of the reaction mixture into two or more components, includingat least one substantially liquid component which comprises watersoluble protein.
 32. The method of claim 31, wherein the step ofseparating comprises separating the at least a portion of the reactionmixture into at least one substantially liquid component and at leastone substantially solid-containing component.
 33. The method of claim31, wherein any emulsion present in said method is maintained at anamount at or below a predetermined level.
 34. The method of claim 33,wherein the level of emulsion present is maintained at or below about5%.
 35. The method of claim 33, wherein the level of emulsion present ismaintained at or below about 2%.
 36. The method of claim 33, wherein thelevel of emulsion present is maintained at or below about 1%.
 37. Themethod of claim 34, wherein the level of emulsion present is maintainedat or below about 0.5%.
 38. The method of claim 31, wherein the step ofseparating comprises separating the at least a portion of the reactionmixture using a slanted filter screen to yield at least onesubstantially liquid component and a substantially solid component. 39.The method of claim 31, wherein the slanted filter screen has a meshsize of between about 1 and about 200 mesh.
 40. The method of claim 31,wherein the separating step further comprises separating the at leastone substantially liquid component into at least a first fractioncomprising a water-soluble protein and at least a second fractioncomprising a water-insoluble protein.
 41. The method of claim 40,wherein the step of separating the at least one substantially liquidcomponent comprises centrifugation.
 42. The method of claim 31, whereinthe reaction mixture is separated into a first component comprisingprimarily an aqueous solution, a second component comprising primarilylipids, and a third component comprising primarily solid matter.
 43. Themethod of claim 31, wherein the step of separating comprises pumping thereaction mixture out of the inactivation reactor.
 44. The method ofclaim 31, wherein the step of hydrolyzing comprises conveying thereaction mixture through the hydrolysis area with at least one feederscrew.
 45. The method of claim 31, wherein the step of hydrolyzingcomprises hydrolyzing the reaction mixture in a tube-shaped reactor. 46.The method of claim 31, wherein the step of inactivating comprisesconveying the reaction mixture through the inactivation area with atleast one feeder screw.
 47. The method of claim 43, wherein at least oneof the feeder screws rotates clockwise and counter-clockwise atdifferent times during the inactivation step.
 48. The method of claim31, further comprising the step of pumping oil present in the reactionmixture away from the reaction mixture, or the step of decanting oilpresent in the reaction mixture, or both.
 49. The method of claim 48,wherein oil is pumped away from the hydrolysis area, the inactivationarea, or both.
 50. The method of claim 31, wherein prior to the step ofseparating, the reaction mixture in the inactivation area is agitated tosubstantially suspend solid matter present in the inactivation area. 51.The method of claim 31, wherein prior to the step of hydrolyzing, theprotein-containing raw material is collected in pieces in a collectionarea.
 52. The method of claim 51, wherein, prior to hydrolysis, thecollected pieces of raw material are processed to reduce the size of thepieces.
 53. The method of claim 52, wherein the size of the pieces isfrom about 15 mm to about 50 mm.
 54. The method of claim 52, wherein thesize of the pieces is 300 mm or more.
 55. The method of claim 31,wherein the raw material comprises material derived from the groupconsisting of fish, animal and plant material.
 56. The method of claim55, wherein the raw material comprises material derived from fish. 57.The method of claim 31, wherein the raw material is hydrolyzed at a rateof two tons per hour.
 58. The method of claim 31, wherein the step ofhydrolyzing is carried out as a continuous non-batch process.
 59. Themethod of claim 31, wherein the step of inactivating is carried out as acontinuous non-batch process.
 60. The method of claim 58, wherein thecontinuous non-batch process is capable of continuous hydrolysis for atleast seventy-two hours.
 61. The method of claim 31, wherein the liquidin the reaction mixture is substantially separated from the solids andwater soluble protein is obtained from the liquid.
 62. The method ofclaim 61, wherein the yield of water soluble protein obtained from themethod is at least about 50 percent by weight of the weight of proteincontained in the raw material.
 63. The method of claim 61, wherein theyield of water soluble protein obtained from the method is at leastabout 60 percent by weight of the weight of protein contained in the rawmaterial.
 64. The method of claim 61, wherein the yield of water solubleprotein obtained from the method is at least about 70 percent by weightof the weight of protein contained in the raw material.
 65. The methodof claim 61, wherein the yield of water soluble protein obtained fromthe method is about 70 percent by weight of the weight of proteincontained in the raw material.
 66. A product containing water solubleprotein obtained from the method of claim
 61. 67. A product according toclaim 66, wherein the raw material comprises fish material, and whereinthe product is soluble in water at room temperature, is substantiallylipid free, and comprises one or more amino acids derived from fish. 68.The product of claim 66, wherein the one or more amino acids derivedfrom fish comprise lysine and methionine.
 69. The product of claim 67,wherein the product is substantially free of asparagine or glutamine.70. The product of claim 67, wherein the product comprises taurine. 71.The product of claim 66, wherein the biological digestibility of theproduct is at least 70%.
 72. The product of claim 66, wherein thebiological digestibility of the product is at least 80%.
 73. The productof claim 66, wherein the biological digestibility of the product is atleast 90%.
 74. An apparatus for the hydrolysis of protein-containing rawmaterial, said raw material also containing solid matter, the apparatuscomprising: means for hydrolyzing said raw material by reacting areaction mixture comprising said raw material and at least one enzymepresent in said area, wherein the reaction mixture contains both solidsand liquid, and wherein upon hydrolysis, said reaction mixture furthercomprises hydrolysis product; means for substantially inactivating theenzyme present in the reaction mixture; and means for separating atleast a portion of the reaction mixture into two or more components,including at least one substantially liquid component which compriseswater-soluble protein; wherein said apparatus maintains any emulsionpresent in the liquid in the reaction mixture below a predeterminedlevel.
 75. A plant for the continuous hydrolysis of a reaction mixtureof a protein containing animal or vegetable raw material, preferably araw material in the form of by products or waste products from theprocessing of foodstuffs, into at least a liquid phase (13) and at leasta solid phase (12) where the plant comprises a preparation section (1) ahydrolysis section (4) connected thereto, an inactivation section (7)connected to the hydrolysis section (4) and a final processing section(17) connected to the inactivation section, where the hydrolysis section(4) is of the type which comprises at least one substantiallytube-shaped hydrolysis reactor (6) having a first feeder screw (20) forconveying a reaction mixture of enzyme and raw material through the atleast one tube-shaped hydrolysis reactor (6) and onward into theinactivation section (7) which has at least one inactivation reactor (8)connected to the hydrolysis section (4) with an inlet end (9) and anexit end (10) positioned opposite to it, characterized by the exit end(10) of the at least one inactivation reactor (8) having at last oneoutlet (14) for the solid phase (12) and at least one outlet (16) forthe liquid phase (13) positioned at a distance from the outlet (14) forthe solid phase (12).
 76. A plant according to claim 75, characterizedby the inactivation reactor (8) having a second feeder screw (24) forshifting the content of the inactivation reactor (8) onward towards theoutlets (14, 16).
 77. A plant according to claim 75, characterized bythe inactivation reactor (8) having a third feeder screw (25) arrangedat its bottom for shifting the sedimented solid matter onward and outthrough the outlet (14) for the solid phase (12).
 78. A plant accordingto claim 75, characterized by at least one of the feeder screws (20, 24,25) being of the type, which is arranged for rotating clockwise in adetermined first period of time, and anti-clockwise in a determinedsecond period of time.
 79. A plant according to claim 75, characterizedby at least one of the feeder screws (20, 24, 25) being designed withscoops or sheets (22) in an area at the periphery of the threads (22) ofthe feeder screws (20, 24, 25).
 80. A plant according to claim 75characterized by the outlets (16) for the liquid phase (14) comprising afat outlet for a fatty fraction and at least one protein outlet for anaqueous fraction which contains ingredients selected from the group ofwater soluble amino acids, peptides and/or proteins, water-insoluble orheavily dissolvable amino acids, peptides and/or protein, or mixtures ofthese ingredients.
 81. A plant according to claim 75, characterized bythe fact that at the outlet (16) for the liquid phase (14), means (18)are arranged for the purpose of mixing an aqueous phase, comprisingdissolved and non-dissolved ingredients of protein origin, with thefatty phase.
 82. A plant according to claim 81 characterized by themeans for mixing the aqueous phase with the fatty phase being a blenderimpeller (18) or a circulation pump.
 83. A plant according to claim 81characterized by the fact that water soluble and water insolubleingredients of protein origin and the fatty fraction are separated fromeach other in a continuously operating decanter or tricanter.
 84. Amethod for continuously hydrolyzing a reaction mixture of a proteincontaining animal or vegetable raw material into a liquid phase (13) anda solid phase (12) in a plant according to claim 54, comprising thesteps of: dividing up the raw material; admixing the raw material withenzyme; enzymatically hydrolyzing the raw material in a determinedperiod of time; inactivating enzymes which are present in the reactionmixture, in an inactivation reactor (8), continuously letting out thesolid phase (12) and the liquid phase (14) from the reaction mixture inthe inactivation reactor (8), characterized by the liquid phase (13)comprising a fatty fraction and an aqueous fraction with a content ofdissolved and non-dissolved ingredients of protein origin, the fattyfraction and the aqueous fraction being let out from the inactivationreactor (8) continuously either separately at identical or differentrates or as a collective homogenized suspension.
 85. A method accordingto claim 84, characterized by the dissolved and non-dissolvedingredients of protein origin and the fatty phase subsequently beingseparated in a tricanter or a decanter.
 86. A method according to claim84, characterized by the method comprising an introductory step in whichmetal parts are separated out from the raw material.
 87. Proteinhydrolysate manufactured by the plant according to claim
 75. 88.Application of a protein hydrolysate according to claim 87 directly orafter additional processing as nutrition or a nutritional supplement forhumans or animals.
 89. A plant and a method for continuous hydrolysis ofa protein containing animal or vegetable raw material and application ofthe resulting hydrolysis products.
 90. Protein hydrolysate manufacturedby the plant according to the method of claim 84.